The electrical systems of automobiles, boats, aircraft, and other vehicles present numerous wiring problems. It is often necessary that wires must run through compartments without introducing environmental leakage between or from the compartments. Devices and methods for passing electrical wiring through a surface such as a wall or bulkhead are frequently sought. The connections between in-tank fuel pumps and fuel level sensors to the electrical wiring harness outside of the fuel tank are especially problematic, because the openings in the gas tank, through which the wires must pass, pose leakage problems due to pressurized gas vapors and capillary seepage of liquid fuel along the insulated wires.
In the manufacture of automotive fuel tanks, a current practice is to rivet brass posts perpendicularly through round holes in a steel plate which is subsequently fastened to a larger opening in the fuel tank. The posts themselves are sealed to the steel plate by tight attachment through individual plastic grommets. A further plastic shell is assembled in the area of the posts to aid subsequent attachment of electrical wires and to protect the posts from mechanical damage. Wires are simultaneously connected to the posts on the other side of the plate during riveting, and this is facilitated by crimping eyelets beforehand to the end of the wires which are slipped over the posts prior to riveting the posts to the plate. The wires are then connected inside the tank to the fuel pump and level sensor. Outside of the tank, wires must be attached to the posts after the tank is mounted to the automobile.
One problem with the current practice of fuel tank connections is that a blind connection is required. The hook-up is typically made between the harness wiring and in-tank devices without the installer being able to see precisely which connections are being made. The connection also creates servicing problems because the tank must often be removed during servicing of the vehicle, requiring disconnection of the wires from the posts.
Although the use of "jumper" wires or short wires connected to the posts prior to installation of the fuel tank might solve the blind attachment and service problems, another connection is required along the electrical path between the jumpers and the wire harness. Additional connections are not particularly desirable. Every connection tends to degrade the electrical integrity of the system and to increase costs.
Jumper wires are normally used either wholly within the fuel tank or outside of it, and therefore do not solve the problem of capillary seepage, which in current applications results from fuel seeping between the perpendicular posts and the plastic grommets and between the plastic grommets and the steel plate.
A further seepage problem arises when stranded wire is passed through a grommet, because leak paths around and between the strands may be created due to the flexible movement of the stranded wire.
A connector is therefore required for passing insulated electrical conductors through a surface or bulkhead while preventing leakage of liquids and gases.